Survival support device

ABSTRACT

Apparatus for providing a breathable gas to an individual in an emergency situation is provided in practice of this invention. The apparatus contains a breathable mixture of gas for a prolonged period and, when actuated, provides about 10 minutes of gas to the user. The gas is contained at high pressure in a lightweight long tube coiled about a combined fill valve, pressure regulator, flow control, pressure gauge, and actuation mechanism. This assembly is in a canister and actuated by perforating a pressure containing diaphragm between the gas storage reservoir and the pressure regulator. The canister is connected to the back of a plastic hood that is fittable over a user&#39;&#39;s head so that the canister is arranged during use at the nape of the user&#39;&#39;s neck so as not to interfere with any emergency operations and, for example, to permit the user to wear a helmet or the like. Gas from the canister passes into the hood at a substantially constant rate and is vented as required through a check valve. An elastic band around the person&#39;&#39;s neck limits leakage.

United States Patent 1 Shonerd 1 Oct. 2, 1973 1 SURVIVAL SUPPORT DEVICE[75] "iifv'iifii? "fiav'id'E.ShOnerdQSama Barbara,

Calif.

22 Filed: Apr. 24, 1972 21 Appl. No.: 247,107

Related US. Application Data [62] Division of Ser. No. 141,781, May10,1971.

Primary Examiner-Richard A. Gaudet Assistant Examiner-Henry J. ReclaAttorney-Christie, Parker & Hale 57 ABSTRACT Apparatus for providing abreathable gas to an individual in an emergency situation is provided inpractice of this. invention. The apparatus contains a breathable mixtureof gas for a prolonged period and, when actuated, provides about 10minutes of gas to the user. The gas is contained at high pressure in alightweight long tube coiled about a combined fill valve, pressureregulator, flow control, pressure gauge, and actuation mechanism. Thisassembly is in a canister and actuated by perforating a pressurecontaining diaphragm between the gas storage reservoir and the pressureregulator. The canister is connected to the back of a plastic hood thatis fittable over a user's head so that the canister is arranged duringuse at the nape of the user's neck so as not to interfere with anyemergency operations and, for example, to permit the user to wear ahelmet or the like. Gas from the canister passes into the hood at asubstantially constant rate and is vented as required through a checkvalve. An elastic band around the persons neck limits leakage.

4 Claims, 11 Drawing Figures SURVIVAL SUPPORT DEVICE CROSS REFERENCE TORELATED APPLICATIONS This is a division, of application Ser. No.141,781, filed May 10, I971.

BACKGROUND Many situations put personnel in a temporary situation wherebreathing of the ambient environment is not practical. A typicalsituation of this sort occurs in shipboard fires where heavy smoke maybe produced and effectively trapped in comparatments within the ship.Personnel within these compartments must evacuate immediately or facesuffocation or severe smoke inhalation injury. When these personnel aredeep within a ship, rapid exiting from the damaged and smoke-filled areamay be virtually impossible in sufficient time to prevent suffocation orsevere injury. It may also be desirable for personnel to remain at theirstations for a limited period in order to perform various emergencytasks before evacuation. It may also be important that personnel rescueinjured or incapacitated people within the affected area and, therefore,they must perform a moderate amount of heavy work during the time thatthe environment is not breathable.

Although but one example of an acute situation requiring auxiliarybreathing apparatus has been mentioned, many other such situations willbe apparent, such as various industrial environments where noxiouschemicals may be present, or in ordinary police and fire work wheresmoke or noxious chemicals may be encountered without a significantamount of advance warning.

When there is advance warning of a requirement for auxiliary breathingapparatus, a variety of conventional equipment is available forself-contained breathing. A more difficult situation arises, however,where the emergency may occur without substantial prior notice, andpersonnel are required to operate in the potentially hazardousenvironment substantially continuously. Again, referring to a shipboardsituation, personnel may work in an engine room or the like for monthsor years without encountering a dangerous situation wherein auxiliarybreathing apparatus is required. When such a situation does occur,however, it is too late to rely on conventional auxiliary breathingequipment, which may be located at fixed stations in the vicinity.

It is, therefore, desirable to provide an emergency breathing apparatuswhich provides breathing support for survival of personnel who may beunexpectedly thrust into an emergency situation wherein the ambientenvironment is unbreathable. Such a survival support device should belightweight and small volume so that it can be carried or worn by aperson substantially continuously during their normal tasks so that isis always at hand when required. It should also have high reliabilityfor long periods of time, substantially complete safety, be confortableto wear, and rapidly usable after prolonged storage.

BRIEF SUMMARY OF THE INVENTION Therefore, in practice of this inventionaccording to a presently preferred embodiment, there is provided asurvival support deivce including a plastic bag fittable over a person'shead for excluding the external atmosphere, a check valve for permittingexhalation, and a pressurized supply of breathable gas connected to thebag in position for wearing at the nape of a user's neck. Preferably,the survival support device stores high pressure gas in an elongatedtube protected by a surrounding canister and wound about a mechanismthat permits long-term storage and instant actuation, as well as flowcontrol for feeding the breathable gas into the plastic bag. Preferably,the mechanism includes a filling vlave, a pressure gauge, and pressureand flow regulators for gas measurement and control. Actuation andover-pressure protection are provided by a rupturable diaphragm anddiaphragm perforating mechanism.

DRAWINGS These and other features and advantages of the invention willbe appreciated as the same becomes better understood by reference to thefollowing detailed description of presently preferred embodiments whenconsidered in connection with the accompanying drawings wherein:

FIG. 1 illustrates a survival support device constructed according toprinciples of this invention in typical use;

FIG. 2 is a rear view of the hood portion of the device of FIG. 1;

FIG. 3 illustrates in cutaway perspective a pressurized gas storage andcontrol system connectable to the hood of FIG. 2;

FIG. 4 illustrates in perspective a control mechanism for the system ofFIG. 3;

FIG. 5 is a cross section through the control mechanism of FIG. 4;

FIG. 6 illustrates in perspective detail ofa diaphragm perforatingplunger from the mechanism of FIG. 5;

FIG. 7 is an end view of the plunger of FIG. 6;

FIG. 8 is a rear view of another embodiment of survival support deviceconstructed according to principles of this invention;

FIG. 9 is an end view of the gas storage and control system of theembodiment of FIG. 8; and

FIG. 10 is a side view, partly cut away, of the system of FIG. 9.

FIG. 11 is a longitudinal cross-sectional view ofa tool used for fillingthe reservoir.

Throughout the drawings, like numerals refer to like parts.

DESCRIPTION FIG. 1 illustrates a typical survival support device as oneembodiment constructed according to principles of this invention.Modifications of the device illustrated in FIG. 1 are set forthhereinafter and adaptation to the components illustrated in FIG. 1 willbe apparent. Thus, as illustrated in the embodiment of FIG. I, a user 11of the survival support device has a hood l2 pulled over his head sothat a breathable atmosphere can be provided within the hood.

In the illustrated arrangement, the hood 12 is made of two essentiallyflat pieces of plastic that are heat or otherwise bonded together toform a sacklike structure, the opening of which is encompassed by anelastic band 13 which during use fits about the user's neck to providesome degree of gas sealing. The front portion 14 of the hood 12 isformed of a transparent plastic so that the user can see throughsubstantially the entire area and find his way out of a dangeroussituation or perform useful tasks while still in the environment. Therear portion 16 of the hood need not be transparent, and is typically anopaque plastic sheet so as to be readily distinguishable from the-frontportion. In addition, a greater variety of mechanical properties areavailable in opaque or translucent plastics than in transparentmaterials, and the structural requirements of the survival supportdevice may be more readily accommodated by employing an opaque ortranslucent material for the rear portion 16 of the hood. The sacklikehood fits loosely over the head of the user so that he can continue towear eyeglasses or the like while using the device.

In the center front of the hood, a conventional check valve 17 ismounted so as to permit gas to be discharged from the interior of thehood to the exterior and inhibit reverse flow of gas. The check valvecan be located in other portions of the hood; however, it is preferredthat the valve be located in a region close to the user's nose or mouthin order to best assure circulation of fresh air or other breathable gasinto this region of the hood.

A gas canister 18, described in greater detail hereinafter, is connectedto the rear portion 16 of the hood by fabric straps 19 (see also FIG.2), which are buckled or otherwise fastened around the canister throughmetal loops 20 (FIG. 3) extending from its cylindrical surface. Thestraps 19 are integral with a fabric sheet 21 in the center back of thehood. The sheet is preferably adhesively bonded to the plastic backportion of the hood or it can be stitched to a fabric insert (not shown)on the inside of the hood for greater strength. The canister 18 is thusconnected in close proximity to the rear portion of the hood near itslower edge so as to lie on the nape of the neck of the user duringoperation. By so positioning the gas canister 18, the users hands andarms are completely free and unconstrained; he can easily turn his headin any desired direction without significant hindrance; his view of thesurroundings is not obscured; and he can perform various required taskswithout problems due to the presence of the canister. The position ofthe canister at the nape of the neck further enables the user to gobareheaded or wear a battle helmet, fire helmet or the like, as desired.Since the gas reservoir is directly connected to the hood, there is nodanger of catching a tube on surrounding objects and cutting off thesupply of breathable gas, as would be the case if the canister were toremain at a persons waist or the like.

During normal situations, that is, in the absence of an emergency, theflexible hood 12 is preferably wrapped around the canister 18 or foldedon one side of it to form a cylindrical package substantially the samesize as the canister. This is preferably stored in a protective plasticbag or the like (not shown), which may be provided with a rip-open panelor seam, so that access to the survival support device is rapidlyobtained in case of an emergency. The plastic bag with the canisterinside is then conveniently carried on the users belt or some otherconvenient location until such time as it is needed. It will be clear,of course, that such survival support devices can also be provided atfixed locations in a region that may be subject to emergency situationsrather than actually be carried by the personnel at all times. It isapparent, of course, that when it is carried directly on the person, theaccess to the survival support device is most reliable and quickest.

When it is desired to use the survival support device, it is removedfrom its protective container or bag (not shown) if employed, and themask or hood 12 is unfolded from the canister 18. After starting theflow of breathable gas into the hood in a manner hereinafter describedin greater detail, the person donning the hood merely dips his headforward so as to catch the front portion of the elastic neck band 13under his chin. He then pulls the rear portion of the elastic neck bandforwardly and upwardly across his face and over the top of his head,stretching it as much as required to do so. Such an operation alsoswings the gas canister 18 over the top of his head so as to lie inposition at the nape of his neck. The elastic band 13 closes about thepersons neck so that the open end of the bag is closed to provide adegree of gas sealing. The position of the transparent front portion 14of the hood can then be adjusted, if needed, by shifting the entirecanister from side to side, or by grasping the sides of the hood totwist it into position, or by grasping the check valve 17 in order tocenter it adjacent the users nose or mouth.

Meanwhile, fresh breathable gas is flowing into the hood, as hereinafterdescribed, so that any noxious gases caught in the hood during thedonning sequence are displaced through the check valve 17. The entireconning sequence and the purge of any remaining noxious materials withinthe mask are typically accomplished in less than about 20 seconds. Flowof breathable gas continues into the hood from the gas canister, and theperson using the survival support device breathes in a normal mannerwith inhaled air being replaced by fresh breathable gas and exhalationslargely expelled through the check valve. The volume of gas entering thehood is sufficient for the person to perform strenuous work for a periodof at least ten minutes, such as may be required for escape from ahazardous situation. This may also permit sufficient time for performingemergency tasks or rescuing other personnel in the hazardous area. Itwill also be noted that two persons can share one survival supportdevice by breathing from the open neck portion in turns, or a secondperson can breath gas from the check valve while being rescued.

HO. 3 illustrates in cutaway perspective a gas storage canister 18 asillustrated in FIG. 1. As illustrated in this embodiment, the canisteris formed of two substantially similar cup-shaped halves 23, one ofwhich may be flared outwardly slightlyand the other rolled inwardly attheir adjoining edges so as to remain centered when fitted together. Ina typical embodiment, the canister is only 5% inches diameter and 6inches long. Mounted within the canister 18 is a double helical coil ofhigh pressure steel tubing 22 within which gas up to about 5,000 psi maybe stored. The elongated tube for storing high pressure gas isparticularly advantageous, since it is capable of storing a reasonablevolume of high pressure gas without a significant total weight. Thus,for example, a survival support device providing ten minutes or more ofbreathable gas can readily be made with a total weight of only about 3%pounds. The tube for gas storage has other advantages, such as, forexample, in case of a leak as might occur from damage or perforation ofthe tubing, the gas tends to leak relatively slowly as compared with asingle cylinder so that no substantially jetting action is caused by theescaping gas.

The tubing 22 can also be made ductile while still being capable ofsupporting the high pressure gases, so

that fragments and shrapnel are not produced in case of severe damage tothe tubing. This latter property is evidenced by a test where a survivalsupport device was perforated by a 0.308 caliber bullet fired transverseto the axis of the canister and which ruptured six coils of the highpressure tubing. The perforated canister rolled off its supportingsix-in-wide shelf and fell to the ground without any noticeable lateralmovement. There was no gas discharge sound discernible from 30 yardsaway, and no visible evidence of blast or jet propulsion. Gas which hadoriginally been stored at 5,000 psi could be heard exiting from thetubing when observers reached the survival support device 40 secondsafter perforation. The rigid canister surrounding the tubing gasreservoir may also help in minimizing jetting action in case of tubeperforation since gas pressure should never build to substantial levelsin the canister even when there is severe leakage from the tubing. Thecanister also helps inhibit shrapnel in case of damage, as well aspreventing damage except in extreme situations.

The tubing 22 forming the gas storage reservoir is supported away fromone end of the canister 18 by a supporting clamp 25, the ends of whichengage the double helix of tubing and the center of which is connectedto a control mechanism 26 mounted concentric with the coil of tubing formost efficient packing density. As seen in FIG. 3, the center of theclamp is between a nut 27 and a gas fitting 28 on the end ofa pressureregulator 29, described in greater detail hereinafter. The gas fitting28 is also connected to the center of one of the end cups 23 of thecanister 18 by a bolt (not shown) threaded into the end of the fitting.The gas fitting is on the low pressure side of the pressure regulator 29and connects to a flexible plastic tube 31 which is passed through theside of the canister and thence through a grommet 32 (FIG. 2) to theinterior of the hood. In this way gas from the regulator passes from thecanister into the hood for breathing by the user of the survival supportdevice.

The control mechanism 26 is further illustrated in perspective in FIG. 4and in a cross-sectional view in FIG. 5. As illustrated therein, thecontrol mechanism has a metal body 35 containing a variety of aperturesand passages within which various portions of the control mechanism arepositioned. The body and the associated mechanisms are preferablycapable of withstanding an internal pressure of at least 5,000 psi toprovide a substantial margin of safety when the gas res ervoir of coiledtubing is charged with a breathable gas at 3,500 psi. Such strengths arereadily attainable since the entire control mechanism is small and theinternal passages and chambers are also of small diameter. Oxygen or anoxygen rich mixture stored at 3,500 psi is sufficient for providingbreathable gas for at least l0 minutes.

A small-diameter metal tube 36 is welded into the control mechanism body35 at one end, and at the other end the tube has a conventional gasfitting 37 for connection to a mating fitting (not shown) at one end ofthe tubing 22 (FIG. 3) forming the principal gas reservoir. The tube 36thus provides fluid communication between the control mechanism and thegas reservoir. The interior of the tube 36 communicates with atransverse passage 38 within the body 35. One end of the transversepassage 38 is closed by a sheet aluminum diaphragm 39, discussed ingreater detail hereinafter.

The other end of the passage 38 communicates with a bore 41 into which aconventional pressure gauge 42 is threaded for indicating the internalpressure in the bore 41, and hence within the gas reservoir.

A passsage having a conical sealing surface 43 communicates with thebore 41 and is sealed by a ball 44 mounted in one end of a plug 46. Theplug 46 includes a pair of opposed fingers 47 for holding the ball inplace and substantially aligned with the axis of the plug. At itsopposite end the plug 46 includes a socket 48 for a hexagonal wrench orthe like so that the plug can be rotated in its threads to bring theball 44 in tight engagement with the conical surface 43 to close thevalve, or to withdraw the ball for opening the valve. A pair of passages49 extend through the plug off of the axis thereof for passing gasthrough the plug from a threaded bore 51 in the body 35. Thus, in orderto fill the gas reservoir, the plug 46is screwed out a short distance toraise the ball 44 off of the conical surface 43. Pressurized gasadmitted through the threaded Bore 51 passes through the passages 49 andinto the interior of the control mechanism body 35' so as to communicatethrough the tube 36 into the gas reservoir. After the reservoir has beencharged to the desired pressure, the plug 46 is screwed down again toseat the ball against the conical surface and thereby close the valve.Although it is preferred to have the fill valve mounted in the controlmechanism body, a fill arrangement can be provided at the end of thecoil of tubing remote from the end connected to the control mechanism. Acheck valve type of fill valve can also be used, but the sealingreliability is not as high as the positive valve illustrated.

After the fill valve has been closed, the survival support device isready for use and can sit on the shelf or be carried by a person forlong periods of time without recharging. The pressure gauge 42 providesan indication of the pressure within the reservoir to confirm that asufficient quantity of gas is stored for at least ten minutes of usewhen the device is activated. If the gauge indicates that the pressurehas dropped due to slow leakage from the system, it is only necessary toreopen the fill valve to bring the pressure back up to the desiredlevel.

Since the survival support device may sit on the shelf or be inactivefor a prolonged period of time and then need to be activated rapidly andreliably on a moments notice, a one shot" actuation mechanism isprovided. The aluminum sheet diaphragm 39 sealing the passage 38 istypically installed as a partially drawn shallow cup that is furtherdeformed into the illustrated form ofa truncated cone by a retainer 52,thereby effecting a tight metal to metal seal between the diaphragm andthe opposed conical surfaces on the retainer and the body. This tightseal persists for long periods of time without deterioration.

An actuator body 53 is threaded into a bore in the control mechanismbody 35 coaxial with the passage 38. This actuator body 53 serves topress the retainer ring 52 tightly against the aluminum diaphragm 39 tohold it in sealing engagement. The actuator body 53 has a cylindricalbore 54 within which a plunger 56 is mounted. A conventional O-ring 57seals the plunger 56 to the cylindrical bore 54 to prevent gas leakagewhen the system is actuated. During static conditions before the deviceis actuated, there is no pressure across the O-ring 57 since the gaspressure is retained by the diaphragm seal 39. The plunger 56 is biasedtowards the diaphragm 39 by a compression spring 58. The plunger isretained in a retracted position, as illustrated in FIG. by a pull pin59, extending through a transverse hole 61 in the end of the plunger.The side of the pull pin 59 bears against the end of the actuator body53 so that when the plunger is in its retracted or cooked position, thespring 58 is under compression.

At the opposite end of the plunger 56 from the pull pin is a perforatingtip 62, also illustrated in the perspective view of FIG. 6 and the endview of FIG. 7. The tip 62 has a diagonal fiat face 63 at about 45degrees to the axis of the plunger. A pair of flat faces 64 about 90apart and parallel to the axis of the plunger intersect the flat face 63so as to form a sharp point at the tip of the plunger adjacent thediaphragm 39. The tip 62 also has a rounded portion 66 which permits itto enter the end passage 38 upon actuation of the device. A gas reliefslot 67 is provided in the tip 62 intersecting the diagonal face 63.

In order to actuate the survival support device, the pull pin 59 iswithdrawn from the hole 61 in the plunger 56. A ring 65 (FIG. 3) isconnected on the end of the pull pin on the outside of the canister sothat it can be withdrawn quickly and easily in an emergency. Thecompression spring 58 then quickly drives the plunger inwardly andcauses the tip 62 to perforate the aluminum sheet diaphragm 39. Gascontained in the gas reservoir flows through the perforated diaphragm byway of the slot 67 and into the bore 54 of the actuator body 53. A pairof transverse passages 68 permit the pressurized gas to flow from withinthe actuator body to a threaded bore 69 into which the pressureregulator 29 is threaded.

The diaphragm and associated actuator mechanism for perforating it thuskeep the pressure regulator isolated from the high pressure gas in thereservoir until the survival support device is actuated and when thepull pin is pulled, the regulator is substantially instantly connectedto the reservoir so that gas quickly flows into the hood.

The pressure regulator 29 has a post 71 threaded into the bore 69 in thecontrol mechanism body 35. An axial passage 72 through most of thelength of the post and ending in a transverse passage 73 permits gas toflow from the bore 69 into a small chamber 74 defined by the sides ofthe post and a movable piston 76. The end of the post 71 has a shallowconical depression that forms a blunt knife edge 77 around the end ofthe post. A cap 75 threaded on the post retains the piston 76 inposition and compresses a compression spring 78. A recessed region inthe inside end of the cap and/or in the end of the piston 76 forms achamber 79 extending over substantially the entire end area of thepiston.

An outlet fitting 81 having a conical cap end 82 fits into the cap 75and is held in place by the nut 27. The conical end 82 thus tightlyengages the inside of the cap to form a gas seal. A small diameterorifice 83 separates the chamber 79 within the cap from the balance ofthe outlet fitting 81 for limiting the flow of gas. The fitting 28 (FIG.3) that provides gas communication to the hood is threaded onto theoutlet fitting 81 when installed in the survival support device.

When gas flows through the passages 72 and 73 through the post 71 fromthe bore 69 of the control device, it fills the chamber 74. It can thenflow past the knife edge 77 into the relatively larger area chamber 79opposite the face of the piston. The flow of gas out of the chamber 79is restricted by the small orifice 83 so that there is a pressurebuildup within the chamber 79 that acts on the face of the piston 76.This increased pressure compresses the spring 78, thereby pressing theinside surface of the piston towards the knife edge 77 on the post. Asthe gap between the piston and knife edge closes, the flow of gas isconstricted so that pressure within the chamber 79 can decrease as gasflows through the orifice 83. A balance between the pressure in thechamber 79 and compression of the spring 78 is quickly achieved so thatthe pressure in the chamber 79 remains substantially constant and,therefore, the flow rate of gas through the flow limiting orifice 83 isalso constant. The areas upon which the high pressure gas within thechamber 74 can act on the piston are balanced so that the magnitude ofthe high pressure within the regulator has negligible effect on thepressure within the outlet chamber 79.

The volume of the outlet chamber 79 is less than 0.01 cubic inch and thediameter of the orifice 83 is typically 0.01 inch. With such dimensionsthe pressure in the chamber 79 is quite responsive and equilibrium israpid. The small volume coupled with the orifice permits a single stageof pressure regulation to be used rather than a double stage, therebyreducing cost, weight, and volume.

Thus, it is seen that the regulator 29 is a combined pressure regulatorand flow control so that substantially constant gas flow is obtainedthrough the outlet fitting 81 despite gross changes in pressure withinthe gas reservoir. In a typical embodiment, the gas in the reservoir isinitially at about 3,500 psi, and this pressure steadily drops towardsambient during the approximately ten minute useful life of a charge ofgas in the survival support device being at about 250 psi after 10minutes. Throughout this broad inlet pressure range, a substantiallyconstant flow of gas passes through the outlet fitting 81 and hence intothe hood 12 for breathing by the user thereof. Tests have shown that thepressure at the outlet of the regulator portion is readily maintained at200 psi, :20 psi, over the entire range from about 5,000 psi down to 250psi on the inlet side. Thus there is substantially constant gas flowinto the hood over a 20 to 1 range of storage reservoir pressures. Ifthe pressure drop across the orifice 83 had a 20 to 1 variation, the gasflow would need to be excessively high initially in order to be adequatenear the end and the total usable time of the survival support devicewould be significantly curtailed.

The sheet aluminum diaphragm 39 seals the gas in the reservoir untilsuch time as the pull pin is pulled, thereby releasing the plunger,perforating the diaphragm, and actuating the survival support device.The diaphragm also serves an additional function in assuring safety ofthe survival support device in case of over-pressurization. Thethickness and strength of the aluminum sheet forming the diaphragm 39 iswell known so that the pressure required to rupture the sheet can bedetermined. The thickness is, therefore, selected so that the diaphragmwill burst at a selected pressure in excess of the pressure of gas inthe reservoir and less than the pressure required to damage othercomponents of the system such as, for example, the tubing forming thereservoir. With such an arrangement, the survival support device cannotbe dangerously over-pressurized since such overpressurization wouldburst the diaphragm 39, permitting the gas to flow through the pressureregulator 29 to be safely exhausted through the hood at a nominal rate.In the absence of overpressurization, the diaphragm remains intact untilactuation when the tip of the plunger pierces FIGS. 8 through illustrateanother embodiment of survival support device constructed according toprinciples of this invention. In some respects, this embodiment ispreferred to that illustrated in FIGS. 1 to 3 since it may be lighter inweight for the same total operating time, is somewhat more comfortableto wear, and occupies a smaller total volume. These advantages comeabout since the coiled tubing forming the gas storage reservoir is bentin a quadrilateral pattern rather than a circular pattern so that theinterior space within the coiled tubing more closely conforms to theexternal configuration of the control mechanism 26. Thus, there is lessunoccupied volume in the gas storage part of the system. In addition,the surrounding metal canister is dispensed with and the controlmechanism is supported directly from the coiled gas reservoir tubing.

FIG. 8 illustrates in back view a hood 86 substantially identical to thehood 12 hereinabove described for fitting over a users head when thesurvival support device is activated. An elastic band 87 at the neck ofthe hood fits snugly around the users neck for inhibiting gas flow.Attached directly to the back of the hood is a sheet plastic muff 88,open at its opposite ends and having a lower flap 89 shown with onecorner curled back in FIG. 8. The muff also comprises an upper flap 91,a corner of which is also curled back in FIG. 8. A embodiment ofstainless steel tubing forming a gas reservoir 92 is contained withinthe muff 88. The gas reservoir 92 is placed within the muff and theupper flap 91 connected to the lower flap 89 by conventional snaps 93.The muff is made so that the plastic is tightly stretched over thereservoir 92 when the snaps are fastened, so that the gas reservoir isheld in position to fit against the nape of a users neck when the hoodis pulled over his head. As in the ebodiment hereinabove described, aplastic tube 94 conducts breathable gas from the gas reservoir through agrommet 96 into the interior of the hood 86 when the survival supportdevice is activated.

Referring now to FIGS. 9 and 10, the gas reservoir 92 is seen in endview and side cutaway, respectively.-As

best seen in the end view of FIG. 9, the gas reservoir is in the form ofa continuous double coil of tubing with an inner coil 97 concentric withan outer coil 98. Each.

of the coils 97 and 98 is somewhat squared off so as to be bent in aquadrilateral figure with rounded corners as compared with the circularcoils of tubing employed in the embodiment hereinabove described andillustrated in FIGS. 1 and 3. Thus, in the first embodiment the gasreservoir is in the form of a right circular cylinder, and in theembodiment illustrated in FIGS. 8 through 10, the gas reservoir is inthe form of a cylinder having a substantially quadrilateral crosssection.

Mounted within the inner coil of tubing 97 forming the gas reservoir isa control mechanism 126 substantially identical to the control mechanism26 hereinabove described and illustrated in FIGS. 4 to 7. The body 135of the control mechanism is approximately rectangular and closely fitswithin the inner coil of tubing 97 so that there is a minimum ofunoccupied volume within the coils forming the gas reservoir. This moreefficient utilization of the volume reduces the total size of the gassupply subsystem of the survival support device.

A bracket 99 having slightly curved ends 101 to conform to the shape ofthe tubing forming the gas reservoir is connected to the controlmechanism 126 by a bolt 102. If desired, a shallow cup over the end ofthe reservoir can be used and this may afford protection for the gaugeand keep the pull pin captive after the device is actuated. The lengthof the control mechanism 126 is less than the coiled length of thetubing forming the gas reservoir, and therefore the opposite end of thecontrol mechanism 126 is bolted to a U-shaped bracket 103 illustrated inthe cutaway view of FIG. 10. The U- shaped bracket 103 has wings 104extending over the end of the gas reservoir 92 so that when assembled,the coils of tubing are clamped together and the control mechanism isfirmly secured thereto within the inner coil. A high pressure gas tube136 connects the body of the control mechanism 126 to the gas reservoir92 by a conventional fitting 137 in the same manner hereinabovedescribed. If the tube 136 is made sufficiently stiff, it may providesupport for one end of the control mechanism, permitting deletion of onebracket.

At the end of the control mechanism approximately flush with the end ofthe gas reservoir 92 is a pressure gauge 142 for monitoring the state ofreadiness of the survival support device. A pull pin 159 attached to aring 165 is employed in the same manner as hereinabove described foractuating the survival support device. Filling of the gas reservoir isaccomplished at the opposite end of the control mechanism, which isrecessed from the end of the gas reservoir. Thus, in both embodiments ofsurvival support device described and illustrated herein, a filling toolelongated enough to fit down to the fill valve is employed so that it isnot necessary to remove the control assembly from the reservoir forfilling.

Such a special fill tool is illustrated in longitudinal cross section inFIG. 11. The fill tool has an inner end fitting having a threaded end111 that is matable with the threaded bore 51 (FIG. 5) in the controlmechanism. A suitable seal (not shown) may be employed between the innerend fitting 110 and the body of the control mechanism for preventing gasleakage when the fill tool is used. Threaded into the opposite end ofthe inner fitting 110' is a tube 112 of a sufficient length to providegas communication between the inner end fitting 110 when threaded into afill valve, and an external gas supply. Connection to the external gassupply (not shown) is made by an outer end fitting 1 13 threaded on theopposite end of the tube 1 12. Both the inner and outer end fittings arealso welded to the tubing 112 after assembly to assure a gas seal andpermanence of the connection. A transverse threaded bore 106communicates with the interior of the outer end fitting 113 forconnection in a conventional manner with a high pressure gas supply.

An axial passage 107 extends along the full length of the fill tool. Ashaft 108 in the passage 107 extends along a principal portion of thelength of the fill tool and has one end extending through the tube 112to butt against the interior of the inner end fitting 110. A hexagonalsocket 109 in the inner end of the shaft 108 mates with a hexagonal key116 having sufficient length that an end thereof can extend beyond theend of the inner end fitting 110. A generally cylindrical sleeve 117press fitted on the key 116 keeps the key captive within the inner endfitting. A flat side 118 on the sleeve 117 permits gas to flow along itslength. A compression spring 119 biases the sleeve 117 and the key 116towards the end of the fill tool so that the end of the key typicallyprotrudes, as illustrated in FIG. 11. The socket 109 in the end of theshaft is sufficiently deep that the key can be depressed as required topermit assembly of the filling tool into the fill valve.

At the opposite end of the shaft 108 an O-ring 121 provides a gas sealto the outer end fitting 113. A shoulder on the shaft 108 bears againsta bushing 122 which engages a conventional thrust bearing 123. Aretainer 124 threaded into the outer fitting 113 preloads the thrustbearing to a degree that permits the shaft to be rotated during use. Ahexagonal socket 125 is provided in the outer end of the shaft 108.

In order to use the fill tool, the threaded portion 111 is tightenedinto the bore 51 (FIG. of the control mechanism. The outer end fitting113 on the fill tool is preferably hexagonal to permit such tightening.When the fill tool is tightened in the control mechanism, the hexagonalkey 116 fits into the hexagonal socket 48 (FIG. 5) in the fill valve.The key and the shaft 108 are free to rotate as the fill valve staysfixed and the fill tool rotates as it is tightened in place. The shaft108 can then be rotated by inserting a conventional hexagonal key (notshown) in the hexagonal socket 125 at the outer end of the fill tool.This motion is transmitted through the length of the fill tool so as toopen the fill valve in the control mechanism by baking the plug 46 outof its bore. High pressure gas may then be admitted through the bore 106in the fill tool to pass around the shaft 108 and past the sleeve 117into the body of the control mechanism where it is transmitted to thegas reservoir as hereinabove described. After the reservoir is chargedto the desired pressure, the fill valve is closed by rotating the shaftof the fill tool and the tool can then be removed and the survivalsupport device is ready for use.

Although but two embodiments of survival support device constructedaccording to principles of this invention have been described andillustrated herein, many modifications and variations will be apparentto one skilled in the art. Thus, for example, three concentric coils oftubing can be employed to form a gas reservoir around a controlmechanism to provide greater storage capability and, hence, greateroperating time or, on the other hand, the total length of the gasreservoir can be decreased as the diameter is increased without changein the operating time. Modifications and variations in the arrangementwithin the-control mechanism can also be provided by one skilled in theart. Many other modifications and variations will be apparent, and it istherefore to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a survival support device comprising:

a substantially impervious flexible bag sufficiently large to fit over auser's head and including a transparent portion adjacent at least afront part of the bag;

means for permitting gas flow out of the bag and inhibiting gas flowinto the bag;

a hollow coil of high pressure tubing for containing a breathable gas athigh pressure;

regulator means within the coil for maintaining a substantially contanstoutlet pressure over a broad range of inlet pressures and asubstantially constant flow from the outlet thereof;

actuator means within the coil for substantially instantly connectingthe regulator means to the reservoir means;

means for supporting the coil from the bag at a rear portion thereofagainst the nape of a users neck, the improvement wherein,

the coil of high pressure tubing comprises at least an outerquadrilateral coil around the regulator means and actuator means whichare substantially rectangular in shape; and

an inner quadrilateral coil substantially concentric with the outer coiland closely conforming to the shape of the regulator means and actuatormeans whereby the total volume of the gas supply is minimized.

2. In a survival support device as defined in claim 1 the furtherimprovement comprising:

a diaphragm between the reservoir means and the regulator means, capableof withstanding a substantial pressure there-across;

a plunger having a perforating tip adjacent the diaphragm;

means for mounting the plunger for movement towards the diaphragm asufficient distance that the perforating tip can penetrate thediaphragm;

means for biasing the plunger towards the diaphragm; and

a removable retaining pin for temporarily holding the plunger away fromthe diaphragm.

3. In a survival support device as defined in claim 1 the furtherimprovement comprising:

a pressure gauge in communication with the coil of tubing;

a pressure containing fill valve in communication with the coil oftubing; and wherein the pressure gauge, the fill valve, and the actuatormeans are all accessible from the ends of the hollow cylinder.

4. In a survival support device as defined in claim 1 the furtherimprovement wherein the transparent portion of the bag is flexible.

t i i i

1. In a survival support device comprising: a substantially imperviousflexible bag sufficiently large to fit over a user''s head and includinga transparent portion adjacent at least a front part of the bag; meansfor permitting gas flow out of the bag and inhibiting gas flow into thebag; a hollow coil of high pressure tubing for containing a breathablegas at high pressure; regulator means within the coil for maintaining asubstantially contansT outlet pressure over a broad range of inletpressures and a substantially constant flow from the outlet thereof;actuator means within the coil for substantially instantly connectingthe regulator means to the reservoir means; means for supporting thecoil from the bag at a rear portion thereof against the nape of auser''s neck, the improvement wherein, the coil of high pressure tubingcomprises at least an outer quadrilateral coil around the regulatormeans and actuator means which are substantially rectangular in shape;and an inner quadrilateral coil substantially concentric with the outercoil and closely conforming to the shape of the regulator means andactuator means whereby the total volume of the gas supply is minimized.2. In a survival support device as defined in claim 1 the furtherimprovement comprising: a diaphragm between the reservoir means and theregulator means, capable of withstanding a substantial pressurethere-across; a plunger having a perforating tip adjacent the diaphragm;means for mounting the plunger for movement towards the diaphragm asufficient distance that the perforating tip can penetrate thediaphragm; means for biasing the plunger towards the diaphragm; and aremovable retaining pin for temporarily holding the plunger away fromthe diaphragm.
 3. In a survival support device as defined in claim 1 thefurther improvement comprising: a pressure gauge in communication withthe coil of tubing; a pressure containing fill valve in communicationwith the coil of tubing; and wherein the pressure gauge, the fill valve,and the actuator means are all accessible from the ends of the hollowcylinder.
 4. In a survival support device as defined in claim 1 thefurther improvement wherein the transparent portion of the bag isflexible.